Cleaning Device

ABSTRACT

A cleaning device for use in cleaning wellbores and other tubular members in subterranean fluid production operations. The cleaning device includes a tool mandrel with cleaning components, such as a scraper assembly and stabilizers, secured thereupon with an attaching ring assembly. The attaching ring assembly includes a housing and a plurality of locking wedges that are movable with respect to the housing.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to systems and methods for cleaning the interior of tubular members. In particular aspects, the invention relates to methods and devices used for constructing and assembling scrapers or other cleaning devices for cleaning wellbore casing.

2. Description of the Related Art

Wellbore cleaning devices include casings scrapers and brushing devices. These mechanisms are used to remove mud, cement sheath, perforation burrs, rust, scale, paraffin, and other debris from the internal surface of wellbore casing. The casing scraper or brush is typically attached to a drill string for operation. The drill string and cleaning device are then disposed within the casing members to be scraped, and rotated.

Typical casing scrapers include a central scraping body and one or more scraping is blades that extend radially outwardly therefrom. Conventional casing scrapers generally fall into one of two categories: rotating and non-rotating. With a rotating scraper, the scraping body and the scraping blades are securely affixed to each other so that both rotate with the drill string. In applications where the drill string is rotated for long periods of time, rotating scrapers can cause serious wear and damage to the interior surface of casing. With a non-rotating scraper, only the scraping body rotates with the drill string.

SUMMARY OF THE INVENTION

The invention provides an improved wellbore cleaning device and a device for use in assembling such a cleaning device. A cleaning device in the form of a scraper device is described which includes stabilizers and a scraper assembly with a plurality of scraper blades. These components preferably rotate about a central tool mandrel. The tool mandrel presents a radially outer surface having an axially-facing stop shoulder. In the described embodiment, the stabilizers and scraper assembly are attached onto the tool mandrel between the stop shoulder and an attaching ring assembly which locks into a groove on the tool mandrel.

In exemplary embodiments, the attaching ring assembly includes an annular housing and a plurality of locking wedges that can be moved radially inwardly and outwardly with respect to the housing. The locking wedges are disposed within an inner radial surface of the housing and are radially separated from one another by gaps in an unlocked condition. In one embodiment, compression springs are disposed between the is housing and the locking wedges to bias the locking wedges radially inwardly toward a locked configuration. In an alternative embodiment, translation screw arrangements are used to translate the locking wedges radially inwardly with respect to the surrounding housing.

In addition, one or more removable threaded screws are used to draw the locking wedges radially outwardly against the housing and into an unlocked condition whereby the attaching ring assembly can be easily slid onto or off of one axial end of the tool mandrel. The one or more threaded screws may be removed to permit the locking wedges to snap into the groove on the tool mandrel, thereby securing the stabilizer and scraper assembly components onto the tool mandrel.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages and further aspects of the invention will be readily appreciated by those of ordinary skill in the art as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference characters designate like or similar elements throughout the several figures of the drawing and wherein:

FIG. 1 is a side, cross-sectional view of an exemplary scraper device which incorporates a retaining ring assembly constructed in accordance with the present invention.

FIG. 2 is a side, cross-sectional view of the scraper device shown in FIG. 1, now with the retaining ring assembly attached to the scraper device.

FIG. 3 is a side view of an exemplary retaining ring assembly apart from the other components of the scraper device and in an unlocked configuration.

FIG. 4 is a side view of the retaining ring assembly shown in FIG. 3, now with the retaining ring in a locked configuration.

FIG. 5 is a side view of an alternative embodiment for a retaining ring assembly constructed in accordance with the present invention and in an unlocked configuration.

FIG. 6 is a side view of the retaining ring assembly of FIG. 5, now in a locked configuration.

FIG. 7 is a close-up view of an exemplary translation screw arrangement used with the retaining ring assembly shown in FIGS. 5 and 6.

FIG. 8 is a close-up view of the translation screw arrangement of FIG. 7, now adjusted so that the locking wedge is translated radially inwardly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1-2 illustrate an exemplary wellbore scraper device 10 that is constructed in accordance with the present invention. The scraper device 10 is useful for incorporation into a wellbore work string and disposed within a wellbore, as is known in the art. The to scraper device 10 includes a generally cylindrical tool mandrel, generally indicated at 12. The tool mandrel 12 defines a central flowbore 14 along its length. An upper axial end 15 of the tool mandrel 12 preferably includes a box-type threaded connection 16 so that the scraper device 10 may be secured to other portions of a wellbore work string (not shown). The lower axial end of the tool mandrel 12 includes a pin-type threaded connection 18.

Preferably, the tool mandrel 12 is made up of a unitary mandrel body 20 and presents an outer radial surface 22 having a number of different diameter portions. There is a lower, enlarged-diameter surface portion 24 which presents an upwardly facing stop shoulder 26. A reduced diameter surface portion 28 lies adjacent the stop shoulder 26. A recess 30 is further provided within the central area of the reduced diameter surface portion 28. In addition, a groove 32 is located within an upper portion of the reduced diameter surface portion 28.

A number of components are retained upon the tool mandrel 12 in a manner so that they are rotatable with respect to the tool mandrel 12. A lower stabilizer 34, of a type known in the art, is disposed around the reduced diameter surface portion 28 of the tool mandrel 12 and positioned against the shoulder 26. Bearings 36, such as roller or needle bearings of types known in the art, are used to allow ease of rotation for the stabilizer 34 about the mandrel 12.

A scraper assembly, generally indicated at 38, is positioned upwardly of the lower stabilizer 34. The scraper assembly 38 may have any of various known configurations. In the depicted embodiment, the scraper assembly 38 includes a retaining sleeve 40 having windows 42 through which scraper elements 44 protrude. The scraper elements 44 are typically biased radially outwardly to protrude through the windows 42 by compression springs (now shown), in a manner known in the art.

It is noted that brushes, magnets or other cleaning members might be used in place of scraper elements 44 to create a cleaning device in accordance with the present invention. It can be seen that the present invention provides a cleaning device that is useful for cleaning tubular members and wellbores that are often used in subterranean fluid is production, such as the production of hydrocarbons.

An upper stabilizer 46 surrounds the tool mandrel 12 above the scraper assembly 38. Like the lower stabilizer 34, the upper stabilizer 46 is provided with bearings 48 which allow for ease of rotation for the stabilizer 46 about the tool mandrel 12.

An attaching ring assembly 50, in accordance with the present invention, is used to secure the various components surrounding the tool mandrel 12 upon the mandrel 12.

An exemplary attaching ring assembly 50 is shown apart from the other components of the scraper assembly 38 in FIGS. 3 and 4. FIGS. 1 and 3 depict the attaching ring assembly 50 in an unlocked condition, wherein it is free to be removed from or slid onto the tool mandrel 12. FIGS. 2 and 4 depict the attaching ring assembly 50 in a locked condition wherein the ring assembly 50 is securely affixed to the tool mandrel 12. The attaching ring assembly 50 is secured into the groove 32 in the tool mandrel 12.

The attaching ring assembly 50 preferably secures the components 34, 38 and 46 axially between the ring assembly 50 and the shoulder 26. The attaching ring 50 includes an annular ring housing 52 having an outer radial surface 54 and an inner radial surface 56. A number of spring recesses 58 are disposed within the inner radial surface 56 of the housing 52. In addition, several openings 60 are disposed through the housing 52.

Several arcuate locking wedges 62 are located within the housing 52. In the depicted embodiment, there are four locking wedges 62. However, there may be more or fewer than four such wedges, if desired. It is noted that there are arcuate gaps or separations 64 located between each of the adjacent wedges 62 when the ring assembly 50 is in the unlocked condition shown in FIGS. 1 and 3. Each of the wedges 62 has an arcuately curved body with a radially outer surface 66 that is shaped to generally conform to the inner radial surface 56 of the housing 52. Each wedge 62 also presents a radially inner surface 68 that generally conforms to the groove 32 in the tool mandrel 12. Each of the locking wedges 62 has one or more spring bores 70 formed within its outer radial surface 66. Although there are two spring bores 70 in each wedge 62 in the depicted embodiment, those of skill in the art will understand that there may be more or fewer than two spring bores 70 in each wedge 62. Each of the spring bores 70 is aligned with one of the spring recesses 58 in the housing 52. A compressible spring member 72 is disposed in each spring bore 70 and its adjacent recess 58. Each wedge 62 also has a threaded blind bore 74 formed within its outer radial surface 66.

In the unlocked condition, a threaded screw 76 is inserted through each opening 60 of the housing and into the threaded blind bore 74 of a neighboring wedge 62. The threaded screws 76 are tightened within the bores 74 to cause each of the wedges to be drawn radially outwardly until the springs 72 are compressed and the outer radial surfaces 66 of the wedges 62 are maintained in contact with the inner radial surface 56 of the housing. In this unlocked condition, the inner radial surfaces 68 of the wedges 62 are expanded to their maximum amount, and the diameter of clearance for the inner radial surfaces 68 of each locking wedge 62 is maintained to be larger than the outer diameter of the upper axial end 15 of the tool mandrel 12. The attaching ring assembly 50 may be to easily slid onto or off of the upper axial end 15 of the tool mandrel 12 in the unlocked condition.

In order to secure the attaching ring assembly 50 to the tool mandrel 12, the attaching ring assembly 50 is slid onto the tool mandrel 12 over the upper axial end 15 (as shown by the phantom position 50 a in FIG. 1) and in the direction of arrow 78 in FIG. 1 Is until the attaching ring assembly 50 is surrounding the groove 32 of the tool mandrel 12.

Then, the threaded screws 76 are removed from the threaded blind bores 74 and openings 60, thereby freeing the locking wedges 62 from their attachment to the housing 52. The compression springs 72 will urge the wedges 62 radially inwardly so that they will snap into a locking engagement within the groove 32 of the tool mandrel 12, as shown in FIG. 2.

FIGS. 5 and 6 depict an alternative embodiment for an attaching ring assembly 50′, which is constructed in accordance with the present invention. Except where otherwise indicated, the attaching ring assembly 50′ is constructed in the same manner as the attaching ring assembly 50 described earlier. Spring recesses 58, spring bores 70 and springs 72 are not present. Instead, the attaching ring assembly 50′ includes a plurality of translation screw assemblies 80. A single translation screw assembly 80 is shown in FIGS. 7 and 8. Each translation screw assembly 80 includes an outer opening 82. In addition, a threaded bore 84 is formed within an adjacent locking wedge 62 and is axially aligned with the outer opening 82. The outer opening 82 includes an annular groove 86, visible in FIGS. 7 and 8. A translation screw 88 is disposed within the outer opening 82 and includes an annular flange 90 proximate its upper end that resides within the groove 86 and permits the translation screw 88 to rotate within the outer opening 82. FIG. 7 shows the translation screw assembly 80 in an initial condition corresponding to the unlocked to condition for the attaching ring assembly 50′. Rotation of the translation screw 88 within the outer opening 82 and bore 84 will cause the screw threads of the screw 88 to rotationally engage the threads of the bore 84 and in so doing, translate the locking wedge 62 radially inwardly and away from the housing 52. It will be understood by those of skill in the art that rotation of each of the translation screws 88 of the attaching ring assembly 50′ will selectively translate each of the locking wedges 62 radially inwardly, thereby moving the attaching ring assembly 50′ from the unlocked condition, shown in FIG. 5 to the locked condition, shown in FIG. 6.

It will further be understood that the compression springs 72 and the translation screw assemblies 80 both serve as mechanisms to urge the locking wedges 62 radially inwardly with respect to the housing 52.

The foregoing description is directed to particular embodiments of the present invention for the purpose of illustration and explanation. It will be apparent, however, to one skilled in the art that many modifications and changes to the embodiment set forth above are possible without departing from the scope and the spirit of the invention. 

1. A cleaning device for use in subterranean fluid production comprising: a tool mandrel; a cleaning assembly radially surrounding the tool mandrel; and an attaching ring assembly for securing the cleaning assembly upon the tool mandrel, the attaching ring assembly comprising: a housing; a plurality of locking wedges that are moveable with respect to the housing between a first position, wherein the wedges are in a radially outward position with respect to the housing, and a second position, wherein the wedges are in a radially inward position with respect to the housing; and wherein the attaching ring assembly is in an unlocked condition with respect to the tool mandrel when the wedges are in the radially outward position and is in a locked condition with respect to the tool mandrel when the wedges are in the radially inward position.
 2. The cleaning device of claim 1 wherein the attaching ring assembly further comprises one or more translation screw arrangements that selectively translate the locking wedges toward the second position.
 3. The cleaning device of claim 2 wherein the one or more translation screw arrangements each comprise: a threaded bore formed within a locking wedge; a translation screw disposed within the threaded bore; and wherein rotation of the translation screw within the bore will translate the locking wedge.
 4. The cleaning device of claim 1 wherein the attaching ring assembly further comprises one or more compressible springs that bias the locking wedges toward the second position.
 5. The cleaning device of claim 4 wherein the attaching ring assembly further comprises: a threaded bore formed in each locking wedge; and a threaded screw that is removably disposed within the threaded bore to releasably retain the locking wedges in the first position.
 6. The cleaning device of claim 1 wherein the housing is an annular ring member.
 7. The cleaning device of claim 1 wherein the tool mandrel presents a groove that the locking wedges are secured within when the attaching ring assembly is in the locked condition.
 8. The cleaning device of claim 1 wherein the cleaning assembly comprises a scraper assembly.
 9. The cleaning device of claim 1 wherein: the tool mandrel further presents an enlarged-diameter portion which presents an axially-facing stop shoulder; and wherein the cleaning assembly is secured upon the tool mandrel between the attaching ring assembly and the stop shoulder.
 10. The cleaning device of claim 1 further comprising a stabilizer radially surrounding the tool mandrel.
 11. A cleaning device for use in subterranean fluid production comprising: a tool mandrel which presents an outer radial surface; the tool mandrel further having an enlarged-diameter portion which presents an axially-facing stop shoulder; a cleaning assembly radially surrounding the tool mandrel; and an attaching ring assembly for securing the cleaning assembly upon the tool mandrel against the stop shoulder, the attaching ring assembly comprising: a housing; a plurality of locking wedges that are moveable with respect to the housing between a first position, wherein the wedges are in a radially outward position with respect to the housing, and a second position, wherein the wedges are in a radially inward position with respect to the housing; and wherein the attaching ring assembly is in an unlocked condition with respect to the tool mandrel when the wedges are in the radially outward position and is in a locked condition with respect to the tool mandrel when the wedges are in the radially inward position.
 12. The cleaning device of claim 11 wherein the attaching ring assembly further comprises one or more translation screw arrangements that selectively translate the locking wedges toward the second position.
 13. The cleaning device of claim 12 wherein the one or more translation screw arrangements each comprise: a threaded bore formed within a locking wedge; a translation screw disposed within the threaded bore; and wherein rotation of the translation screw within the bore will translate the locking wedge.
 14. The cleaning device of claim 11 wherein the attaching ring assembly further comprises one or more compressible springs that bias the locking wedges toward the second position.
 15. The cleaning device of claim 11 wherein the attaching ring assembly further comprises: a threaded bore formed in each locking wedge; and a threaded screw that is removably disposed within the threaded bore to releasably retain the locking wedges in the first position.
 16. The cleaning device of claim 11 wherein the housing is an annular ring member.
 17. The cleaning device of claim 11 wherein the tool mandrel presents a groove that the locking wedges are secured within when the attaching ring assembly is in the locked condition.
 18. The cleaning device of claim 11 wherein the cleaning assembly comprises a scraper assembly.
 19. The cleaning device of claim 11 further comprising a stabilizer radially surrounding the tool mandrel.
 20. A cleaning device for use in subterranean fluid production comprising: a tool mandrel which presents an outer radial surface; the tool mandrel further having an enlarged-diameter portion which presents an axially-facing stop shoulder; a scraper assembly radially surrounding the tool mandrel; and an attaching ring assembly for securing the scraper assembly upon the tool mandrel against the stop shoulder, the attaching ring assembly comprising: a housing; a plurality of locking wedges that are moveable with respect to the housing between a first position, wherein the wedges are in a radially outward position with respect to the housing, and a second position, wherein the wedges are in a radially inward position with respect to the housing; a mechanism to urge the locking wedges toward their inward position; and wherein the attaching ring assembly is in an unlocked condition with respect to the tool mandrel when the wedges are in the radially outward position and is in a locked condition with respect to the tool mandrel when the wedges are in the radially inward position.
 21. The cleaning device of claim 20 wherein the mechanism to urge the locking wedges toward their inward position comprises one or more compression springs.
 22. The cleaning device of claim 20 wherein the mechanism to urge the locking wedges toward their inward position comprises one or more translation screw arrangements.
 23. The cleaning device of claim 20 wherein the attaching ring assembly further comprises: a threaded bore formed in each locking wedge; and a threaded screw that is removably disposed within the threaded bore to releasably retain the locking wedges in the first position.
 24. The cleaning device of claim 20 wherein the tool mandrel presents a groove that the locking wedges are secured within when the attaching ring assembly is in the locked condition.
 25. The cleaning device of claim 20 further comprising a stabilizer radially surrounding the tool mandrel.
 26. The cleaning device of claim 20 wherein the housing is an annular ring member. 